Mechanical air conditioning and refrigeration is accomplished by continuously circulating, evaporating, and condensing a fixed supply of refrigerant in a closed system. Charging or recharging an air conditioning or refrigeration system with refrigerant is done through the low side suction intake fitting with the use of manifold gauges and service hoses. Low-pressure vapor refrigerant is compressed and discharged from a compressor as a high temperature, high-pressure, “superheated” vapor or liquid. The high-pressure refrigerant flows to a condenser, where it is changed to a low temperature, high-pressure liquid. It then flows through a filter dryer to a thermal expansion valve or TXV. The TXV meters the correct amount of liquid refrigerant into an evaporator. As the TXV meters the refrigerant, the high-pressure liquid changes to a low pressure, low temperature, saturated liquid/vapor. This saturated liquid/vapor enters the evaporator and is changed to a low pressure, dry vapor. The low pressure, dry vapor is then returned to the compressor. The cycle then repeats.
The manifold commonly has three refrigeration lines or hoses connected thereto. One line is connected through the manifold to a low pressure gauge and is used in servicing the low pressure side (suction side) of a refrigeration/air conditioning system. A second line is connected through the manifold to a high pressure gauge and is used in servicing the high pressure side (discharge side) of a refrigeration/air conditioning system. A third line is connected to a port which commonly connects the ports in the manifold leading to the high and low pressure lines. The third line is used for connection to a refrigerant source or some other pressurized source, or a vacuum source.
Flow control is performed by means of high pressure and low pressure valves at the manifold. Whenever any of the aforementioned three lines are connected to a refrigeration or air conditioning system, the lines can be bled to purge the air from the lines so as to avoid contamination of the refrigeration system with air (and moisture in that air).
Many refrigeration compressors incorporate a suction service valve and a discharge service valve. These are used to allow refrigeration gauges to be attached to the system; and, if needed, they are used to isolate the compressor from the rest of the system. Typically the low pressure (suction side) valve and high pressure (liquid side) valve differ in construction. These service valves each include recessed safety sockets that can be opened or closed with a standard refrigeration service wrench, but require different size hex key adapters to do so. For example, a 3/16th inch hex key is operable to open and close the high side service valve, while a 5/16th inch hex key is operable to open and close the low side service valve.
A conventional hex key adapter that is capable of opening and closing both the high side and low side valves may be a stacked adapter; it includes a distal end that is keyed to the low side valve socket, and a middle portion that is keyed to the high side valve socket. Difficulties arise, however, because the length of the distal end key must be sufficient to operatively connect with the low side valve, but not be so long as to prevent the middle portion from operatively connecting to the high side valve. In fact, the tolerance is so tight that often the technician strips the high side valve because the hex key barely reaches the hex socket, does not become fully engaged in that socket, and upon attempted rotation, strips the socket. Shortening the length of the distal end allows the middle portion to reach the socket effectively, but may result in the distal end key not effectively reaching its corresponding hex socket, and thus stripping the same upon attempted rotation.
It therefore would be desirable to provide an adapter that is operable to open and close both the low side valve and high side valve while reducing or eliminating the risk of stripping one or more of the valves.
Other objects and advantages of the present invention and advantageous features thereof will become apparent as the description proceeds herein.